Custom Thick-Wall Quartz Capillaries

Parameter	Factory Standard	Manufacturing Limit
OD	1–15 mm	—
ID (bore)	0.1–3 mm	—
Wall thickness	0.5–6 mm	—
OD/ID ratio	3:1–20:1	Higher ratios on request
Bore tolerance	±0.01–0.03 mm	Tighter, confirmed per order
Concentricity	≤8% of wall	Tighter, confirmed per order
Length	10–500 mm	—

Inquiry

Thick-wall quartz capillaries provide additional quartz around a controlled bore for handling stiffness, protected alignment and secondary machining. This series covers 0.5–6 mm walls, with the thick-wall classification starting at a wall thickness of 1 mm.

OD/ID Ratio as the Main Design Variable

For a concentric round section, nominal wall thickness is (OD − ID) / 2. Select the ID from the flow or inserted component, then choose the OD for mounting and the required section. Include any material that will be removed by grinding, flats or shoulders: the finished minimum wall, rather than the starting wall alone, determines the available quartz section.

Minimum Wall and Bore Centering

Nominal ID and OD do not identify the thinnest wall if the bore is offset. Specify bore position and the minimum permitted wall around the circumference, particularly where secondary machining approaches the channel. A thick nominal wall does not remove the need to control centering or to inspect the finished section.

Pressure Duty Requires Full Geometry Review

Wall thickness by itself is not a pressure rating. A pressure-duty assembly needs review of ID, OD, finished length, temperature, surface condition, supports and end connections, followed by appropriate assembly validation. Include the pressure and thermal cycle on the drawing or RFQ. The product family provides geometry for evaluation; no universal working-pressure limit is assigned to all thick-wall capillaries.

Thick-Wall Geometry

OD, ID and Minimum Wall Must Agree

Controlled Feature	Reference Capability / Requirement
Bore ID	Specified from flow, insert or alignment function
Outer Diameter	Selected from the required wall section and holder fit
Wall Thickness	Overall series 0.5–6 mm; thick-wall classification starts at ≥1 mm
Wall Tolerance	Agreed by OD, ID, wall and length; ±0.10–0.15 mm is a 1–3 mm reference-wall band, not a universal series tolerance
Concentricity	Bore position controlled to preserve minimum wall around the circumference
Wall Uniformity	Minimum and maximum wall limits used where strength or machining stock matters
Length	Cut to drawing with straightness added only where assembly requires it
Pressure / Mechanical Duty	Reviewed from complete geometry, temperature, surface condition and end connectionNo universal pressure rating is assigned to the product family

Wall Selection

Choose Wall for Stiffness, Protection or Machining Stock

Reference Wall	Design Benefit	Check Before Quote
1.0–1.5 mm	More handling stiffness around a small bore	ID, OD and cut length
1.5–2.0 mm	Protected alignment channel and improved section for holding	Concentricity and minimum wall
2.0–3.0 mm	Additional stock for ground OD, flats or secondary features	Finished envelope and machining drawing

Delivery Forms

Thick-Wall Capillaries as Structural Quartz Blanks

Small Bore / Large ODHigh wall-to-bore ratio for stiffness and protected alignment

Centered Thick-Wall TubeControlled bore position maintains usable wall around the full section

Ground OD or EndsFinished fit surfaces and axial length for holders and flow cells

Machining BlankExtra quartz section for flats, shoulders, tips and custom interfaces

Applications

Where Extra Quartz Section Adds Function

High-Pressure Flow CellsThick-wall starting geometry for assemblies whose final pressure duty is separately validated

Nozzle & Restrictor BodiesSmall controlled bore with quartz stock for external fit and handling

Structural Liners & SupportsProtected channels and stiff alignment components in analytical or thermal equipment

Need a thick-wall capillary reviewed as a complete geometry?Send ID, OD, minimum wall, concentricity, length, temperature and end-connection drawing.

Open the Capillary Configurator

Engineering Data

Grade-Qualified Material Purity

Electric-fused / flame-fused quartz: SiO₂ ≥99.99%; synthetic JGS1-grade fused silica: ≥99.999%. Grade and lot certificate govern supplied material.

Thick-wall means wall thickness ≥1 mm. This product series also includes 0.5–<1 mm transitional-wall configurations, covering an overall wall range of 0.5–6 mm.